package com.company.作业;

import java.util.Scanner;

public class sb {
    public static void main(String[] args) {
        Scanner in=new Scanner(System.in);
        System.out.println("请输入圆的半径");
         int a=in.nextInt();
         a(a);
    }
    public static void a(int a){
        double area;double pai=3.14;
        area=pai*a*a;
        System.out.println("圆的面积="+area);
    }

}








